Sakana AI: Fugu Ultra
sakana/fugu-ultra
Access Fugu Ultra from Sakana AI using Puter.js AI API.
Get Started// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';
puter.ai.chat("Explain quantum computing in simple terms", {
model: "sakana/fugu-ultra"
}).then(response => {
document.body.innerHTML = response.message.content;
});
<html>
<body>
<script src="https://js.puter.com/v2/"></script>
<script>
puter.ai.chat("Explain quantum computing in simple terms", {
model: "sakana/fugu-ultra"
}).then(response => {
document.body.innerHTML = response.message.content;
});
</script>
</body>
</html>
# pip install openai
from openai import OpenAI
client = OpenAI(
base_url="https://api.puter.com/puterai/openai/v1/",
api_key="YOUR_PUTER_AUTH_TOKEN",
)
response = client.chat.completions.create(
model="sakana/fugu-ultra",
messages=[
{"role": "user", "content": "Explain quantum computing in simple terms"}
],
)
print(response.choices[0].message.content)
curl https://api.puter.com/puterai/openai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_PUTER_AUTH_TOKEN" \
-d '{
"model": "sakana/fugu-ultra",
"messages": [
{"role": "user", "content": "Explain quantum computing in simple terms"}
]
}'
Model Card
Fugu Ultra is a learned multi-agent orchestration system from Tokyo-based Sakana AI that routes tasks across a swappable pool of frontier LLMs behind a single OpenAI-compatible endpoint.
Rather than relying on one monolithic model, Fugu Ultra dynamically assigns Thinker, Worker, and Verifier roles to specialist agents, then synthesizes their outputs into a single response. The underlying coordination is grounded in Sakana's TRINITY and Conductor research, published at ICLR 2026.
It targets demanding, multi-step problems: complex reasoning, code review, agentic workflows, cybersecurity analysis, and research tasks. On LiveCodeBench it scores 93.2, ahead of several frontier competitors, and it matches leading models on GPQA-Diamond and Humanity's Last Exam.
Fugu Ultra is a strong choice for developers who need frontier-level quality on hard tasks without committing to a single model provider.
Context Window 1M
tokens
Max Output 128K
tokens
Input Cost $5
per million tokens
Output Cost $30
per million tokens
Release Date Jun 24, 2026
Model Playground
Try Fugu Ultra instantly in your browser.
This playground uses the Puter.js AI API — no API keys or setup required.
Frequently Asked Questions
You can access Fugu Ultra by Sakana AI through Puter.js AI API. Include the library in your web app or Node.js project and start making calls with just a few lines of JavaScript — no backend and no configuration required. You can also use it with Python or cURL via Puter's OpenAI-compatible API.
Yes, it is free if you're using it through Puter.js. With the User-Pays Model, you can add Fugu Ultra to your app at no cost — your users pay for their own AI usage directly, making it completely free for you as a developer.
| Price per 1M tokens | |
|---|---|
| Input | $5 |
| Output | $30 |
Fugu Ultra was created by Sakana AI and released on Jun 24, 2026.
Fugu Ultra supports a context window of 1M tokens. For reference, that is roughly equivalent to 2,000 pages of text.
Fugu Ultra can generate up to 128K tokens in a single response.
Yes — the Fugu Ultra API works with any JavaScript framework, Node.js, or plain HTML through Puter.js. Just include the library and start building. See the documentation for more details.
Get started with Puter.js
Add Fugu Ultra to your app without worrying about API keys or setup.
Read the Docs View Tutorials